The above mentioned capsules, used in machines for making these beverages, comprise in their simplest form, the following:    a rigid, cup-shaped container comprising a perforatable or perforated bottom and an upper aperture provided with a rim (and usually, but not necessarily, having the shape of a truncated cone);    a dose of extract or infusion beverage product contained in the rigid container; and    a length of sheet obtained from a web for sealing the aperture of the rigid container and designed (usually but not necessarily) to be perforated by a nozzle which supplies liquid under pressure.
Usually, but not necessarily, the sealing sheet is obtained from a web of flexible material.
In some cases, the capsules may comprise one or more rigid or flexible filtering elements. For example, a first filter (if present) may be located on the bottom of the rigid container. A second filter (if present) may be interposed between the seal and the product dose.
The capsule made up in this way is received and used in specific slots in machines for making beverages.
At present, capsules of this kind are made using machines which operate in “step by step” fashion.
One known example of machines of this kind is described in patent publication WO 2010/007633.
The machine described in WO 2010/007633 comprises a conveyor belt which is closed in a loop around two power-driven horizontal-axis pulleys in such a way as to form an upper, active section and a lower, non-operative return section.
The belt comprises a series of successive pockets which receive the rigid containers fed by a corresponding station located above the active section of the belt.
As it moves stepwise along a feed direction, the active section of the belt positions each pocket with a respective rigid container in it under a series of stations for making up the capsule.
Basically, the station which feeds the rigid container is followed by at least one station for dosing the product into the rigid container, a station for closing the upper aperture of the rigid container with a length of film (for example by heat-sealing) and, lastly, a station for feeding out the capsules thus made.
It should be noted, however, that along the rectilinear, active section of the belt, there may be further, auxiliary stations, for example to check capsule weight and to form the length of film, filter application stations, means for removing rejects, and so on.
However, a single production line combined with step by step operation has proved to be low in productivity per unit time.
To overcome this problem, the belt was made wider in the direction transversal to the direction of belt feed so as to form two or more juxtaposed rows of pockets for receiving respective rigid containers.
This technical choice, however, meant augmenting the installed stations, like those mentioned above, placed side by side in a horizontal plane transversely to the feed direction of the active section of the belt.
While this solution on the one hand partly increased the overall productivity of the machine per unit time, on the other it made the machine more cumbersome and decidedly more expensive and increased the risks of machine shutdowns owing to the large number of devices operating along the active section of the belt.
This structural choice does not therefore balance the overall costs with the results of operational productivity and does limit the operating speed of the machine.